There are many situations when it is desirable for people to know of the approximate arrival time of a particular transportation vehicle shortly before the vehicle is to arrive at a particular destination. For example, a person having to pick up a friend or relative at a commercial bus station either has to call the bus station to find out the approximate arrival time (information which is oftentimes unavailable) or plan on arriving at the bus station prior to the scheduled arrival time of the bus and hope the bus is not delayed.
Another example is in the commercial fishing industry, wherein fish markets, restaurants, and other establishments desire to purchase fish immediately upon arrival of a commercial fishing boat at a port. Currently, such establishments, in order to ensure being able to purchase the freshest catch often depend on predetermined schedules of fishing fleets, which are not always accurate or reliable.
Still another example involves school children that ride school buses. School children who ride buses to school often have to wait at their bus stops for extended lengths of time because school buses arrive at particular bus stops at substantially different times from one day to the next. The reason is that school buses are not always the best-maintained vehicles on the roads, frequently operate during rush hour traffic, and must contend with congested urban/suburban conditions. As a result, school children are forced to wait at their bus stops for long periods of time, oftentimes in adverse weather conditions, on unlit street comers, or in hazardous conditions near busy or secluded streets. If it is raining, snowing, windy and cold, and/or even dark, such conditions can be unhealthy and unsafe for children.
Thus, generally, it would be desirable for a user to know when a vehicle (such as a bus, truck, train, plane, or the like) is (a) a particular time period (for example, number of minutes or seconds) away from arriving at a destination, (b) a particular distance (for example, number of miles or height) away from the destination, or (c) at a particular location among a set of location points, so that the user can adjust his/her schedule and avoid arriving too early or too late.
In the past, in order to combat the arrival time problem in the context of school buses, student notification systems have been employed that use a transmitter on each bus and a receiver inside each student home. U.S. Pat. No. 4,713,661 to Boone et al. and U.S. Pat. No. 4,350,969 describe systems of this type. When the school bus and its on-board transmitter come within range of a particular home receiver, the transmitter sends a signal to notify the student that his/her school bus is nearby. While such notification systems work satisfactorily under certain circumstances, nevertheless, these systems are limited by the range of the transmitters and require the purchase of relatively expensive receivers for each student. In addition, such systems provide little flexibility for providing additional information to the students, such as notifying them of the delayed arrival of a bus, alternative bus route information, or information regarding important school events.